Winter’s here, and it’s time to keep little ones wrapped up warm. For Emperor penguins however, nesting in the most inhospitable reaches of Antarctica where temperatures plummet to -60°C, that’s not so easy.

But this Christmas brings a gripping tale of incredible endurance and devotion set in what must be the harshest nursery on the planet. It’s the true story of how one baby penguin, dubbed the Snow Chick, hatches late and then survives against all the odds.

The dedication of his parents to rear their precious offspring defies belief – as does the determination of the camera crew attempting to capture it all.

A new documentary captures an emperor penguin chick's first few months of life

Snow Chick fends off marauding petrels with their scythe-like beaks and evades hungry leopard seals. He gets lost in the frozen wastes and is then found as he’s close to death. He copes with raging blizzards and even kidnap attempts by broody females without chicks of their own.

Every day of his life is a battle for survival, and every day was a battle for footage too as wildlife film-maker Frederique Olivier and her assistant Martin Passingham camped in the polar wastes to document his journey.

They were using pioneering techniques that enabled them to film close-up, despite strict international regulations that prevent humans from coming within 20 metres of the penguins. The team, who also filmed last year’s award-winning penguin documentary Spy In The Huddle, used robot cameras operated by remote control and hidden inside fake penguins, rocks and plastic eggs.

They were rewarded with the most extraordinary bird’s-eye images, achieved without disrupting the flock, that follow the first few months in little Snow Chick’s life – and his desperate struggle to survive is to be shown for the first time on BBC1.

A camera disguised as a baby chick helps capture a unique look into the lives of the penguins

Frederique and Martin were completely cut off for the best part of a year as they filmed. The Emperor penguins’ breeding grounds are 60 miles from the coast where no helicopter could reach them in the winter months and conditions were too dangerous for aeroplanes.

They sent their footage back to the UK via a satellite link, where producer John Downer – the man behind ground-breaking spy-cam documentaries on tigers, elephants and bears – watched with his heart in his mouth as Snow Chick battled through one test after another. ‘There were 2,000 new chicks in the colony,’ he explains, ‘but Snow Chick was unmistakeable because he was the smallest.

It looked as though he wasn’t going to hatch at all, and then one of the other males brought his newborn across and that chick’s calls, sounding halfway between a cat and a gull, encouraged Snow Chick to come out.’

Male Emperor penguins endure two months without food as they sit on their partner’s eggs to incubate them, and then keep the chicks tucked safely in feathery pouches like tea cosies under their bellies.

Meanwhile the females must trek the 60 miles to the sea to hunt for fish, and then make the long trek back before regurgitating the meal for their chicks. It’s an arduous journey over broken ice floes where leopard seals wait below the surface ready to pounce, lunging out of the water with their snake-like heads to snatch unwary birds.

The penguins struggle on even though they’re not built for walking: with their ungainly waddle they can barely manage 2mph and the round trip can take more than a week.

And when the females finally reach the colony they face a fresh challenge – the problem of locating their mate. ‘Even to penguins,’ John says, ‘other penguins look alike.’ So the males organise an identity parade, waddling past in single file so their partners can pick them out.

They squawk too, and it’s these unique callsigns that most often enable couples to find each other again.

Now it’s dad’s turn to go fishing, but Snow Chick doesn’t want to emerge from his father’s pouch. Despite the bitter winds and snowstorms, under those feathers it’s a snug 37°C. The transfer from parent to parent must be done in a single fluid movement while the adults press their bellies together; if the newborn chick stands on the snow for more than a couple of seconds he’ll die of exposure.

An emperor penguin keeps her egg warm

When the penguins reach about six weeks old they start to explore, but because his playmates are so much bigger and stronger Snow Chick is often pushed away from the gang. He decides to strike out on his own, and being so little he quickly disappears from his mum’s view. The mother’s wave of panic as she realises her chick is missing is palpable.

The robot camera tracks the chick as he approaches one female after another in search of his mother and is driven away each time. It’s not until he appears on the point of collapsing and freezing to death that his mum finds him and takes him into her pouch.

For the crew, this near-disaster was hard to bear. ‘There was nothing Frederique could do,’ says John. ‘They couldn’t try to save it because not only did they have to keep their distance, the chick would not survive without its mother.’

But other females did attempt to muscle in and claim the chick as their own. One sequence, revealing behaviour never filmed before, shows a gaggle of maiden aunts surrounding Snow Chick and almost smothering him to death with their embraces before his dad rescues him.

As the Antarctic spring arrives, the ice begins to melt and the coastline creeps nearer and nearer to the breeding grounds. This brings two unwelcome visitors: Adelie penguins and giant petrels. The Adelies are boisterous little birds, strutting around with their chests puffed out and their heads tipped back.

If the Emperors look like head waiters, Adelies are more like nightclub bouncers. They effectively timeshare the breeding grounds with the Emperors, taking them over as summer approaches, and as they start to arrive they try to bully the Emperor chicks out. Adelies aren’t big creatures but Snow Chick is smaller, and once the newcomers move in he’s constantly pecked and hassled.

The Adelies are a nuisance – but the petrels are downright dangerous because they kill penguin chicks with their sharp bills and eat them. Ironically it’s now down to the maiden aunts, who act as babysitters when the parents go fishing, to see off these ferocious birds.

Snow Chick almost falls prey as a petrel seizes him by the downy feathers on his back. But his baby plumage is starting to moult and it comes away in the scavenger’s beak, allowing him to scramble to safety – another miraculous escape.

At this point, back at the studio in Bristol, John and his team were awaiting each week’s film sequences with tense anticipation. They’d followed Snow Chick’s battle for survival this far, but he had one more huge challenge ahead – and if he didn’t make it the disappointment would be unbearable.

Both at home and on the polar ice cap, the film-makers had become intensely attached to their star, yet there was nothing they could do to help him.

After one last meal of regurgitated fish, the adults leave the chicks when they’re about four months old. Despite all their dedication, Emperors do not shepherd their babies to the sea. They simply waddle away, and when the chicks get hungry enough instinct will propel them towards the ocean to fish for themselves.

By now it’s December, mid-summer, and Frederique and Martin were expecting the chicks to move out within days, meaning they could be home with their families for Christmas. But the young penguins held out for another four weeks, apparently assuming their parents would return with more fish. So the film crew decided to stay on too: to miss the end of Snow Chick’s story would be unthinkable.

Because the ice melts quickly in the mild temperatures, the chicks – when they finally set out – reach the sea within a couple of days. But as they crowd at the water’s edge, apprehensive about taking the plunge for the first time, the melt almost proves fatal for Snow Chick. An ice floe crumbles into the sea, taking him with it. Lurking below are the leopard seals, but Snow Chick manages to scramble to safety as the jaws of a seal snap savagely behind him.

And that, sadly, is the last viewers will see of Snow Chick. As hundreds of young penguins leap into the ocean, nimbly evading the seals, our hero is lost to the camera’s view.

At five months old he’s ready to tackle adult life in the wild, and because the team were not allowed to get too close none of the chicks were tagged. With luck, Snow Chick will spend the next four years at sea before choosing a mate and making the gruelling trek back to the breeding grounds to incubate a chick of his own.

But by then he will be utterly indistinguishable from all the other Emperors. The camera will never be able to pick him out again, but the story of his struggle to survive those first crucial months of his life will surely be the most heartwarming show on TV this Christmas.